/Engine/Source/Runtime/MovieScene/Public/Evaluation/PersistentEvaluationData.h
A key to a piece of data that is potentially shared between multiple tracks
struct FSharedPersistentDataKey
FMovieSceneEval...
Operand
The operand that this key relates to (may be invalid where the data pertains to root tracks)
FMovieSceneShar...
UniqueId
The actual shared ID